Others resembled corals and shrimps. At least 30
appear to be new to science, said Julian Gutt, chief scientist of an
expedition that was part of the International Polar Year research
effort set to launch on March 1. The researchers catalogued about 1,000
species in an area of the Antarctic seabed where warming temperatures
are believed to have caused the collapse of overlying ice shelves,
affecting the marine life below.

“This is virgin geography,” said expedition member
Gauthier Chapelle. “If we don’t find out what this area is like now
following the collapse of the ice shelf, and what species are there, we won’t have any basis to know in 20 years’ time what has changed and how global warming has altered the marine ecosystem.”

The expedition also found sea lilies, sea cucumbers and sea urchins
thriving on the sea floor—these species are usually found in much
deeper waters where food is scarce, but the ice shelves probably made
food scarcer than it would usually be at that shallow depth.

In the Weddell Sea off the east coast of the
Antarctic Peninsula, 10,000 square kilometers of seabed was sealed off
from the surface for thousands of years by the 100-m thick Larsen A and B ice shelves. When these ice shelves collapsed in recent years, the area was opened up to colonization by species that could not have survived there before [Original News Story].

The international team of scientists recently
completed a 10-week expedition of the area. Using a remote operating
vehicle, they were able to do the first comprehensive survey of life on
the seabed. Before the ice shelves collapsed, the only access
scientists had to the area was through holes drilled in the ice.

Ice shelves form when creeping glaciers reach the
continent’s coast and begin to float on the ocean. They usually lose
mass via icebergs that calve off and float out to sea gradually, but
the Larsen A and B shelves both suddenly and surprisingly collapsed.
Since 1974, a total of 13,500 square kilometers (about half the size of
New Jersey) of ice shelves have disintegrated—a phenomenon linked to
global warming, as temperatures have risen faster in Antarctica than anywhere else in world.

In general, the expedition found that animals were less abundant in the Larsen A and B areas compared to other areas of the Antarctic.
Animals in the area were only one percent as abundant as other parts of
the Weddell Sea, which Gutt suspects is somehow related to the
availability of food.

New species?

One of the main aims of the expedition was to survey
both indigenous life-forms and creatures that had moved in after the
collapse to take advantage of the newly opened environment.

Gutt said that 95 percent of the animals the
expedition found were probably indigenous and just 5 percent had moved
in after the ice shelves collapsed, but even that small percentage
indicated a shift in biodiversity and species composition in the area which will probably continue.

“Life at the sea floor obviously reacts very slowly
to this very climactic change in the environmental conditions," Gutt
said. “[It] needs hundreds to thousands of years until a new community
has fully developed, if this will happen at all.”

One creature new to the neighborhood was the fast-growing, gelatinous sea squirt, which the scientists found in several dense patches.

Iceberg damage

The expedition also found scours created by icebergs
that calved from the ice sheets and ran aground on the sea bed,
destroying the life in the area, but the damage wasn’t as bad as
expected.

“I expected more, because if there are thousands of
icebergs disintegrated, or calved, in a very short period of only a few
months, then I expected that everything would be destroyed. But it was
not,” Gutt said.

The expedition actually found more evidence of
disturbance outside the Larsen ice shelf area at points where many
icebergs must pass.

But in the areas icebergs had destroyed, Gutt said, signs of life were returning.